<?php
/**
 * CodeIgniter
 *
 * An open source application development framework for PHP
 *
 * This content is released under the MIT License (MIT)
 *
 * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 *
 * @package    CodeIgniter
 * @author    EllisLab Dev Team
 * @copyright    Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
 * @copyright    Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
 * @license    http://opensource.org/licenses/MIT	MIT License
 * @link    https://codeigniter.com
 * @since    Version 1.0.0
 * @filesource
 */
defined('BASEPATH') OR exit('No direct script access allowed');

/**
 * Zip Compression Class
 *
 * This class is based on a library I found at Zend:
 * http://www.zend.com/codex.php?id=696&single=1
 *
 * The original library is a little rough around the edges so I
 * refactored it and added several additional methods -- Rick Ellis
 *
 * @package        CodeIgniter
 * @subpackage    Libraries
 * @category    Encryption
 * @author        EllisLab Dev Team
 * @link        https://codeigniter.com/user_guide/libraries/zip.html
 */
class CI_Zip
{

    /**
     * mbstring.func_override flag
     *
     * @var    bool
     */
    protected static $func_override;
    /**
     * Zip data in string form
     *
     * @var string
     */
    public $zipdata = '';
    /**
     * Zip data for a directory in string form
     *
     * @var string
     */
    public $directory = '';
    /**
     * Number of files/folder in zip file
     *
     * @var int
     */
    public $entries = 0;
    /**
     * Number of files in zip
     *
     * @var int
     */
    public $file_num = 0;
    /**
     * relative offset of local header
     *
     * @var int
     */
    public $offset = 0;
    /**
     * Reference to time at init
     *
     * @var int
     */
    public $now;
    /**
     * The level of compression
     *
     * Ranges from 0 to 9, with 9 being the highest level.
     *
     * @var    int
     */
    public $compression_level = 2;

    /**
     * Initialize zip compression class
     *
     * @return    void
     */
    public function __construct()
    {
        isset(self::$func_override) OR self::$func_override = (extension_loaded('mbstring') && ini_get('mbstring.func_override'));

        $this->now = time();
        log_message('info', 'Zip Compression Class Initialized');
    }

    // --------------------------------------------------------------------

    /**
     * Add Directory
     *
     * Lets you add a virtual directory into which you can place files.
     *
     * @param    mixed $directory the directory name. Can be string or array
     * @return    void
     */
    public function add_dir($directory)
    {
        foreach ((array)$directory as $dir) {
            if (!preg_match('|.+/$|', $dir)) {
                $dir .= '/';
            }

            $dir_time = $this->_get_mod_time($dir);
            $this->_add_dir($dir, $dir_time['file_mtime'], $dir_time['file_mdate']);
        }
    }

    // --------------------------------------------------------------------

    /**
     * Get file/directory modification time
     *
     * If this is a newly created file/dir, we will set the time to 'now'
     *
     * @param    string $dir path to file
     * @return    array    filemtime/filemdate
     */
    protected function _get_mod_time($dir)
    {
        // filemtime() may return false, but raises an error for non-existing files
        $date = file_exists($dir) ? getdate(filemtime($dir)) : getdate($this->now);

        return array(
            'file_mtime' => ($date['hours'] << 11) + ($date['minutes'] << 5) + $date['seconds'] / 2,
            'file_mdate' => (($date['year'] - 1980) << 9) + ($date['mon'] << 5) + $date['mday']
        );
    }

    // --------------------------------------------------------------------

    /**
     * Add Directory
     *
     * @param    string $dir the directory name
     * @param    int $file_mtime
     * @param    int $file_mdate
     * @return    void
     */
    protected function _add_dir($dir, $file_mtime, $file_mdate)
    {
        $dir = str_replace('\\', '/', $dir);

        $this->zipdata .=
            "\x50\x4b\x03\x04\x0a\x00\x00\x00\x00\x00"
            . pack('v', $file_mtime)
            . pack('v', $file_mdate)
            . pack('V', 0) // crc32
            . pack('V', 0) // compressed filesize
            . pack('V', 0) // uncompressed filesize
            . pack('v', self::strlen($dir)) // length of pathname
            . pack('v', 0) // extra field length
            . $dir
            // below is "data descriptor" segment
            . pack('V', 0) // crc32
            . pack('V', 0) // compressed filesize
            . pack('V', 0); // uncompressed filesize

        $this->directory .=
            "\x50\x4b\x01\x02\x00\x00\x0a\x00\x00\x00\x00\x00"
            . pack('v', $file_mtime)
            . pack('v', $file_mdate)
            . pack('V', 0) // crc32
            . pack('V', 0) // compressed filesize
            . pack('V', 0) // uncompressed filesize
            . pack('v', self::strlen($dir)) // length of pathname
            . pack('v', 0) // extra field length
            . pack('v', 0) // file comment length
            . pack('v', 0) // disk number start
            . pack('v', 0) // internal file attributes
            . pack('V', 16) // external file attributes - 'directory' bit set
            . pack('V', $this->offset) // relative offset of local header
            . $dir;

        $this->offset = self::strlen($this->zipdata);
        $this->entries++;
    }

    // --------------------------------------------------------------------

    /**
     * Byte-safe strlen()
     *
     * @param    string $str
     * @return    int
     */
    protected static function strlen($str)
    {
        return (self::$func_override)
            ? mb_strlen($str, '8bit')
            : strlen($str);
    }

    // --------------------------------------------------------------------

    /**
     * Read the contents of a file and add it to the zip
     *
     * @param    string $path
     * @param    bool $archive_filepath
     * @return    bool
     */
    public function read_file($path, $archive_filepath = FALSE)
    {
        if (file_exists($path) && FALSE !== ($data = file_get_contents($path))) {
            if (is_string($archive_filepath)) {
                $name = str_replace('\\', '/', $archive_filepath);
            } else {
                $name = str_replace('\\', '/', $path);

                if ($archive_filepath === FALSE) {
                    $name = preg_replace('|.*/(.+)|', '\\1', $name);
                }
            }

            $this->add_data($name, $data);
            return TRUE;
        }

        return FALSE;
    }

    // --------------------------------------------------------------------

    /**
     * Add Data to Zip
     *
     * Lets you add files to the archive. If the path is included
     * in the filename it will be placed within a directory. Make
     * sure you use add_dir() first to create the folder.
     *
     * @param    mixed $filepath A single filepath or an array of file => data pairs
     * @param    string $data Single file contents
     * @return    void
     */
    public function add_data($filepath, $data = NULL)
    {
        if (is_array($filepath)) {
            foreach ($filepath as $path => $data) {
                $file_data = $this->_get_mod_time($path);
                $this->_add_data($path, $data, $file_data['file_mtime'], $file_data['file_mdate']);
            }
        } else {
            $file_data = $this->_get_mod_time($filepath);
            $this->_add_data($filepath, $data, $file_data['file_mtime'], $file_data['file_mdate']);
        }
    }

    // ------------------------------------------------------------------------

    /**
     * Add Data to Zip
     *
     * @param    string $filepath the file name/path
     * @param    string $data the data to be encoded
     * @param    int $file_mtime
     * @param    int $file_mdate
     * @return    void
     */
    protected function _add_data($filepath, $data, $file_mtime, $file_mdate)
    {
        $filepath = str_replace('\\', '/', $filepath);

        $uncompressed_size = self::strlen($data);
        $crc32 = crc32($data);
        $gzdata = self::substr(gzcompress($data, $this->compression_level), 2, -4);
        $compressed_size = self::strlen($gzdata);

        $this->zipdata .=
            "\x50\x4b\x03\x04\x14\x00\x00\x00\x08\x00"
            . pack('v', $file_mtime)
            . pack('v', $file_mdate)
            . pack('V', $crc32)
            . pack('V', $compressed_size)
            . pack('V', $uncompressed_size)
            . pack('v', self::strlen($filepath)) // length of filename
            . pack('v', 0) // extra field length
            . $filepath
            . $gzdata; // "file data" segment

        $this->directory .=
            "\x50\x4b\x01\x02\x00\x00\x14\x00\x00\x00\x08\x00"
            . pack('v', $file_mtime)
            . pack('v', $file_mdate)
            . pack('V', $crc32)
            . pack('V', $compressed_size)
            . pack('V', $uncompressed_size)
            . pack('v', self::strlen($filepath)) // length of filename
            . pack('v', 0) // extra field length
            . pack('v', 0) // file comment length
            . pack('v', 0) // disk number start
            . pack('v', 0) // internal file attributes
            . pack('V', 32) // external file attributes - 'archive' bit set
            . pack('V', $this->offset) // relative offset of local header
            . $filepath;

        $this->offset = self::strlen($this->zipdata);
        $this->entries++;
        $this->file_num++;
    }

    // --------------------------------------------------------------------

    /**
     * Byte-safe substr()
     *
     * @param    string $str
     * @param    int $start
     * @param    int $length
     * @return    string
     */
    protected static function substr($str, $start, $length = NULL)
    {
        if (self::$func_override) {
            // mb_substr($str, $start, null, '8bit') returns an empty
            // string on PHP 5.3
            isset($length) OR $length = ($start >= 0 ? self::strlen($str) - $start : -$start);
            return mb_substr($str, $start, $length, '8bit');
        }

        return isset($length)
            ? substr($str, $start, $length)
            : substr($str, $start);
    }

    // --------------------------------------------------------------------

    /**
     * Read a directory and add it to the zip.
     *
     * This function recursively reads a folder and everything it contains (including
     * sub-folders) and creates a zip based on it. Whatever directory structure
     * is in the original file path will be recreated in the zip file.
     *
     * @param    string $path path to source directory
     * @param    bool $preserve_filepath
     * @param    string $root_path
     * @return    bool
     */
    public function read_dir($path, $preserve_filepath = TRUE, $root_path = NULL)
    {
        $path = rtrim($path, '/\\') . DIRECTORY_SEPARATOR;
        if (!$fp = @opendir($path)) {
            return FALSE;
        }

        // Set the original directory root for child dir's to use as relative
        if ($root_path === NULL) {
            $root_path = str_replace(array('\\', '/'), DIRECTORY_SEPARATOR, dirname($path)) . DIRECTORY_SEPARATOR;
        }

        while (FALSE !== ($file = readdir($fp))) {
            if ($file[0] === '.') {
                continue;
            }

            if (is_dir($path . $file)) {
                $this->read_dir($path . $file . DIRECTORY_SEPARATOR, $preserve_filepath, $root_path);
            } elseif (FALSE !== ($data = file_get_contents($path . $file))) {
                $name = str_replace(array('\\', '/'), DIRECTORY_SEPARATOR, $path);
                if ($preserve_filepath === FALSE) {
                    $name = str_replace($root_path, '', $name);
                }

                $this->add_data($name . $file, $data);
            }
        }

        closedir($fp);
        return TRUE;
    }

    // --------------------------------------------------------------------

    /**
     * Write File to the specified directory
     *
     * Lets you write a file
     *
     * @param    string $filepath the file name
     * @return    bool
     */
    public function archive($filepath)
    {
        if (!($fp = @fopen($filepath, 'w+b'))) {
            return FALSE;
        }

        flock($fp, LOCK_EX);

        for ($result = $written = 0, $data = $this->get_zip(), $length = self::strlen($data); $written < $length; $written += $result) {
            if (($result = fwrite($fp, self::substr($data, $written))) === FALSE) {
                break;
            }
        }

        flock($fp, LOCK_UN);
        fclose($fp);

        return is_int($result);
    }

    // --------------------------------------------------------------------

    /**
     * Get the Zip file
     *
     * @return    string    (binary encoded)
     */
    public function get_zip()
    {
        // Is there any data to return?
        if ($this->entries === 0) {
            return FALSE;
        }

        return $this->zipdata
        . $this->directory . "\x50\x4b\x05\x06\x00\x00\x00\x00"
        . pack('v', $this->entries) // total # of entries "on this disk"
        . pack('v', $this->entries) // total # of entries overall
        . pack('V', self::strlen($this->directory)) // size of central dir
        . pack('V', self::strlen($this->zipdata)) // offset to start of central dir
        . "\x00\x00"; // .zip file comment length
    }

    // --------------------------------------------------------------------

    /**
     * Download
     *
     * @param    string $filename the file name
     * @return    void
     */
    public function download($filename = 'backup.zip')
    {
        if (!preg_match('|.+?\.zip$|', $filename)) {
            $filename .= '.zip';
        }

        get_instance()->load->helper('download');
        $get_zip = $this->get_zip();
        $zip_content =& $get_zip;

        force_download($filename, $zip_content);
    }

    // --------------------------------------------------------------------

    /**
     * Initialize Data
     *
     * Lets you clear current zip data. Useful if you need to create
     * multiple zips with different data.
     *
     * @return    CI_Zip
     */
    public function clear_data()
    {
        $this->zipdata = '';
        $this->directory = '';
        $this->entries = 0;
        $this->file_num = 0;
        $this->offset = 0;
        return $this;
    }
}
